33 Concurrency support library [thread]

33.10 Futures [futures]

33.10.4 Class future_­error [futures.future.error]

namespace std { class future_error : public logic_error { public: explicit future_error(future_errc e); const error_code& code() const noexcept; const char* what() const noexcept; private: error_code ec_; // exposition only }; }
explicit future_error(future_errc e);
Effects: Initializes ec_­ with make_­error_­code(e).
const error_code& code() const noexcept;
Returns: ec_­.
const char* what() const noexcept;
Returns: An ntbs incorporating code().message().